--- /dev/null 2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.api.directives.test/src/org/graalvm/compiler/api/directives/test/BlackholeDirectiveTest.java 2017-02-15 16:56:26.156935392 -0800
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.api.directives.test;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.graalvm.compiler.api.directives.GraalDirectives;
+import org.graalvm.compiler.core.test.GraalCompilerTest;
+import org.graalvm.compiler.nodes.ParameterNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+
+/**
+ * Tests for {@link GraalDirectives#blackhole}.
+ *
+ * There are two snippets for each kind:
+ *
+ * - blackhole<Kind>Snippet verifies that dead code elimination is prevented by the
+ * blackhole directive.
+ *
- <kind>Snippet verifies that dead code elimination does happen if the blackhole
+ * directive is not there.
+ *
+ *
+ */
+public class BlackholeDirectiveTest extends GraalCompilerTest {
+
+ @Retention(RetentionPolicy.RUNTIME)
+ @Target(ElementType.METHOD)
+ private @interface BlackholeSnippet {
+ boolean expectParameterUsage();
+ }
+
+ @BlackholeSnippet(expectParameterUsage = false)
+ public static int booleanSnippet(int arg) {
+ boolean b = arg > 3;
+ if (b) {
+ return 1;
+ } else {
+ return 1;
+ }
+ }
+
+ @BlackholeSnippet(expectParameterUsage = true)
+ public static int blackholeBooleanSnippet(int arg) {
+ boolean b = arg > 3;
+ GraalDirectives.blackhole(b);
+ if (b) {
+ return 1;
+ } else {
+ return 1;
+ }
+ }
+
+ @Test
+ public void testBoolean() {
+ test("booleanSnippet", 5);
+ test("blackholeBooleanSnippet", 5);
+ }
+
+ @BlackholeSnippet(expectParameterUsage = false)
+ public static int intSnippet(int arg) {
+ int x = 42 + arg;
+ return x - arg;
+ }
+
+ @BlackholeSnippet(expectParameterUsage = true)
+ public static int blackholeIntSnippet(int arg) {
+ int x = 42 + arg;
+ GraalDirectives.blackhole(x);
+ return x - arg;
+ }
+
+ @Test
+ public void testInt() {
+ test("intSnippet", 17);
+ test("blackholeIntSnippet", 17);
+ }
+
+ private static class Dummy {
+ private int x = 42;
+ }
+
+ @BlackholeSnippet(expectParameterUsage = false)
+ public static int objectSnippet(int arg) {
+ Dummy obj = new Dummy();
+ int ret = obj.x;
+ obj.x = arg;
+ return ret;
+ }
+
+ @BlackholeSnippet(expectParameterUsage = true)
+ public static int blackholeObjectSnippet(int arg) {
+ Dummy obj = new Dummy();
+ int ret = obj.x;
+ obj.x = arg;
+ GraalDirectives.blackhole(obj);
+ return ret;
+ }
+
+ @Test
+ public void testObject() {
+ test("objectSnippet", 37);
+ test("blackholeObjectSnippet", 37);
+ }
+
+ @Override
+ protected boolean checkLowTierGraph(StructuredGraph graph) {
+ BlackholeSnippet snippet = graph.method().getAnnotation(BlackholeSnippet.class);
+ ParameterNode arg = graph.getParameter(0);
+ if (snippet.expectParameterUsage()) {
+ Assert.assertNotNull("couldn't find ParameterNode(0)", arg);
+ Assert.assertFalse("expected usages of " + arg, arg.hasNoUsages());
+ } else {
+ Assert.assertTrue("expected no usages of ParameterNode", arg == null || arg.hasNoUsages());
+ }
+ return true;
+ }
+}